Two dihydropyrimidinone derivatives (DHPM) were synthesized via the multi-component reaction, the yield of the synthesis reached 90%, and their structures were proved by IR, ¹H and ¹³C NMR spectroscopy. The identified molecules were used for studying the corrosion inhibition of XC48 carbon steel in 0.5 mol L⁻¹ H₂SO₄ solution. The inhibitory potentials of these compounds were determined by electrochemical methods exploiting the potentiodynamic polarization curves (Tafel method) and electrochemical impedance spectroscopy. Surface phenomena have been illustrated by atomic force microscopy. The results obtained show that the synthesized molecules are effective inhibitors, whose efficiency corrosion inhibition depends on the architecture of their structure, and it is proportional to the concentrations; it exceeds 94% for one of these inhibitors. The adsorption of these compounds on the metal surface approached the Langmuir’s adsorption isotherm. Furthermore, the electronic properties obtained using density function theory are in a good consensus with the experimental efficiencies of inhibition. The molecular dynamics simulations have allowed also simulating the interactions between the inhibitors and the metallic surface.

The current study focuses on the chemical composition, and evaluation of antioxidant and antibacterial activity of the aerial parts of Centaurea resupinata subsp. dufourii. Using different chromatographic methods nine compounds 1–9 were isolated. The structural identification of isolated compounds was achieved using several spectroscopic methods NMR techniques (¹H NMR, ¹³C NMR, COSY, HSQC, HMBC) and mass spectroscopy (ESI-MS) and by comparison with literature data. The structures of these compounds were identified as nicotiflorin (1), apigetrin (2), chrysoeriol (3), apigenin (4), chrysin (5), daucosterol (6), β-sitosterol (7), taraxastrerol (8) and lupeol (9). The antibacterial and antioxidant activities of ethyl acetate and n-butanol extracts have been evaluated. The antioxidant activity was assessed in vitro using DPPH radical scavenging method, which showed that ethyl acetate extract possessed an interesting antioxidant potential (IC₅₀ = 36.263 ± 0.005 μg/mL).

The aim of this work is the phytochemical study of the butanolic extract of the aerial parts of Veronica rosea. Four compounds 1–4 have been isolated using different chromatographic methods. The structures of these compounds were determined by NMR spectral analysis and mass spectroscopy. The adsorption and anticorrosion effects of this extract were investigated towards the corrosion of copper in 1 M HNO₃ aqueous by the weight loss technique and potentiodynamic polarization. The results showed that the butanolic extract is a good inhibitor and the inhibition efficiency increases with increasing of concentration of the inhibitor. The adsorption of this extract on the copper specimen surface was spontaneous and obeyed the Langmuir’s adsorption isotherm. Large value of adsorption equilibrium Constant (K _ads = 35 L g⁻¹) was obtained. The polarization experiments confirmed the data obtained by gravimetric weight-loss. Tafel plot of polarization curves indicates that the extract acts as a mixed type inhibitor.

The aim of this work is the phytochemical study of the butanolic extract of the aerial parts of Veronica rosea. Four compounds 1–4 have been isolated using different chromatographic methods. The structures of these compounds were determined by NMR spectral analysis and mass spectroscopy. The adsorption and anticorrosion effects of this extract were investigated towards the corrosion of copper in 1 M HNO₃ aqueous by the weight loss technique and potentiodynamic polarization. The results showed that the butanolic extract is a good inhibitor and the inhibition efficiency increases with increasing of concentration of the inhibitor. The adsorption of this extract on the copper specimen surface was spontaneous and obeyed the Langmuir’s adsorption isotherm. Large value of adsorption equilibrium Constant (K _ads = 35 L g⁻¹) was obtained. The polarization experiments confirmed the data obtained by gravimetric weight-loss. Tafel plot of polarization curves indicates that the extract acts as a mixed type inhibitor.

Copper destined for electrical cabling require a compromise of mechanical properties and electrical resistivity. The drawing process accompanied by the formation of crystalline defects, such as gaps and dislocations, which leads to the increase in hardness, and therefore to the increase in resistivity, a very important characteristic for the conductivity and the efficiency of the cable. The scope of this work is to investigate the phenomenon of deformation texture evolution while copper wire drawn destined for electric cable-making and to understand its relationship with the electrical conductivity. In this study, we notice that the hardness and the resistivity increase with an increase of the deformation level. On the other hand, a slight decrease in the resistivity of the wires was observed after a holding time of 30 min at 260°C. The annealing of wires at 260°C for 9 min of holding time leads to a recrystallisation especially for high deformations and a gradual return of the mechanical properties and of the microstructure towards a state close to the state of the wire rod with the extension of time . The recrystallization texture is composed of the same components as the drawing texture, fibers <111>//ND (Normal Direction) and <001>//ND. The decrease in the intensity of the fiber after annealing is observed. On the other hand, the fiber <001> // ND remains stable.

Transprotection of acetals to bis(methoxyphenyl)methyl (BMPM) ethers can be efficiently achieved in the presence of copper dibromide as catalyst in acetonitrile at room temperature. Acetals are conveniently and selectively converted to the corresponding mono-protected diol with bis(methoxyphenyl)methyl isopropyl ether (BMPMOiPr) as the reagent. This new practical reagent allows the BMPM transfer to 1,3-dioxolanes or 1,3-dioxanes under copper catalysis. The reaction conditions are also very mild and tolerant to various functional groups, including other protecting groups.

Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields.

Transprotection of acetals to bis(methoxyphenyl)methyl (BMPM) ethers can be efficiently achieved in the presence of copper dibromide as catalyst in acetonitrile at room temperature. Acetals are conveniently and selectively converted to the corresponding mono-protected diol with bis(methoxyphenyl)methyl isopropyl ether (BMPMOiPr) as the reagent. This new practical reagent allows the BMPM transfer to 1,3-dioxolanes or 1,3-dioxanes under copper catalysis. The reaction conditions are also very mild and tolerant to various functional groups, including other protecting groups.

Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields.

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.